Kelp forests are an important marine environment but are being destroyed by changing fishing methods.
DNA from the snot, or blow, is collected after the dolphins have risen to the surface of the water.
Seagrass that takes carbon dioxide from the air "35 times faster than rainforests" to be restored.
Scientists hope tiles made with a 3D printer will attract marine wildlife to a sea wall.
The huge barrel jellyfish, as big as a human, was seen off the coast of Cornwall.